Will Your Weight Loss Program Work? It May Depend on Your Genes

SAN DIEGO — When people take part in a weight loss program, some shed many pounds, while others don't see the scale change at all. Now, early research suggests people's genes may predict whether they will lose weight during a weight loss program.

In the study, the researchers analyzed information from 46 people who took part in an eight-week program that involved changes in diet, exercise and behavior, at a Veterans Affairs facility. The participants also submitted a DNA sample for a test (called Pathway Fit, from the DNA testing company Pathway Genomics) that analyzed 75 genetic markers already known to be linked with certain health conditions or with the body's responses to diet and exercise.

Then, the researchers looked to see whether certain genetic markers could predict which participants had lost 5 percent or more of their body weight by the end of the program and which participants had either lost less than 1 percent of their body weight or gained weight. [The Best Way to Lose Weight Safely]

They found five genetic markers linked with weight loss, and then used these markers to create a mathematical model aimed at predicting weight loss among participants in their weight loss program. When they used the model to try to predict who would successfully lose weight, it was accurate 75 percent of the time.

"Patient weight loss following behavioral modification therapy really varies," said study first author Cecilia Dalle Ore, a medical student at the University of California, San Diego. The findings suggest that people's genes could potentially be used to predict their response to behavioral modification programs, said Dalle Ore, who presented the findings here last Sunday (May 22) at Digestive Disease Week, a scientific meeting focused on digestive diseases.

However, because the new study was small, the model still needs to be validated in future studies with more people, she said.

In the future, a genetic test might help doctors know which patients would be unlikely to do well in a weight loss program, said Dr. Amir Zarrinpar, a gastroenterologist at the University of California, San Diego, and senior a author of the study. [How to Get Started on a Weight Loss Program]

In these cases, doctors could try alternative approaches — instead of embarking on a standard weight loss program, they might try a more intense program first, which could involve meal replacements or weight loss drugs, Zarrinpar said.

"By validating these types of genetic tests and showing that they apply to a general population, we can try to improve patient weight loss treatments. For example, instead of waiting three months to see whether a patient is going to respond or not, you could use this kind of information to say, 'OK, we know this patient's likelihood of succeeding is going to be low. Let's do something else instead,'" Zarrinpar said. "That's what we're going towards."

The study was funded by Pathway Genomics, which markets a genetic test that claims to help people with their diet and fitness based on their genes.